The iridescent colors of the Blue Morpho Butterfly's wings are produced by nanostructures that reflect different wavelengths of light.

The Blue Morpho is common in Central and South America and known for its bright blue wings. However, these iridescent colors are created not by pigments in the wing tissues but instead by the way light interacts with nanometer-sized structures on the Morpho's wing scales. This effect is being studied as a model in the development of new fabrics, dye-free paints, and anti-counterfeit technologies for currency.

In this optical microscope image, light can be seen passing though a silica nanowire on a silica aerogel surface.

New technologies have made it possible to draw glass in long, ultra-smooth wires with uniform diameters in the nanometer range. Because of their extraordinary uniformity, these nanowires have unique properties important in optics and photonics, both of which require precise control of light.

• SIZE: This nanowire is 530 nm long and the radius of the bent wire is 8 µm.

The tree-like structures in this scanning electron microscope image of a cross section of a butterfly wing are on the undersides of the Morpho's wing scale ridges. These microribs reflect light to create iridescent colors.

The gecko's amazing ability to cling to vertical or inverted surfaces is due to the interaction between nanoscale structures on its feet and tiny crevices on the wall or ceiling. The soles of gecko feet are made up of overlapping adhesive lamellae covered with millions of superfine hairs, or setae, each of which branches out at the end into hundreds of spatula-shaped structures. These flexible pads—each measuring only a few nanometers across—curve to fit inside unseen cracks and divots on the surface. The combined adhesion of these millions of pads holds the gecko in place.

Air bubbles trapped beneath a silicon crystal film are shown in this optical microscope image. Light passing through the bubbles creates the circular patterns and colors.

Extremely thin films like these have important electrical properties and therefore find numerous applications in ultra-fast computer chips and high-yield solar cells. This image shows an intermediate stage of their production; trapped air bubbles are removed in later processing.

This is an optical microscope image of a liquid crystal (Cromlyn in water). The colors are created by molecular variations or changes in the crystal's thickness.

Liquid crystals have properties of both liquids and solids: Although they can flow like a fluid, their molecules are highly ordered, like those found in solid crystals. The ubiquitous liquid crystal displays (LCDs) found in everything from watches to cell phones are made possible by devices that rapidly alter the structure of these substances—and therefore the way they interact with light.